Making Whiskey: Distillation

Making Whiskey: Distillation

“No married man is genuinely happy if he has to drink worse whisky than he used to drink when he was single.”
H. L. Mencken

We have taken cereal grains, corn, rye, wheat or barley, and by malting, mashing and fermentation we have a low alcohol content, sugary liquid, a “wash”, which only a dare devil would drink.

To create a smooth, rounded finish with a high alcohol content characteristic of whiskies around the world, the wash must be distilled.  After distillation, the whisky must then be aged in wooden casks to allow the flavor to develop.

Distillation

The wash is distilled, which does two things; firstly it increases the alcohol content and secondly, it removes impurities in the mix, especially methanol.

A still is used to perform the distillation, and in the United States where grain whisky is most commonly made, a Coffey still will be used, but for single malt whiskies an older type of still is used – a pot still.  Distillation is usually repeated a second time, (and rarely for a third time) for most single malt distilleries in Scotland which wish to have their product called “Scotch”, but there are other conditions to be satisfied before this appellation is earned.

Malt Whiskey Distillation

The wash is placed in a wash still which is used to heat the liquid to boiling point, and this causes the alcohol to collect at the top of the still.  The alcohol content is now increased to around 20% and the liquid is known as “low wine”.

The low wine is now placed in a spirit still for a second distillation, but the distiller’s art really comes into play here.  The distillation is divided into three phases or “cuts”; the first distillate, or “foreshot” is extremely strong and toxic and usually is separated and distilled further.  The middle cut is the distillate the stillman is after – it is this which will be separated for maturation.  Finally, the last third, known as “feints” is quite weak and is passed back for further distillation.

The middle cut, known as “new make” is what the stillman will pass on for maturation.  By now, the whisky is around 60% to 75% alcohol proof but still very coarse and rough.

Grain Whisky Distillation

Grain whisky is made using a single distillation, typically using a column still and fractional distillation (the same process which is used to make gas from crude oil).  This is a faster and more efficient process which means the whisky is usually cheaper to buy, but many consider the taste to be inferior to malt whisky.

No matter which distillation process is used, or the wide variations between distillers using the same method, the “new make” is still not finished whiskey – the next stage is maturation or aging in oak casks.